Apparatus for the liquid treatment of threads



Dec. 5, 1950 J. H. GIVENS ET AL 2,533,103 APPARATUS FOR THE LIQUID TREATMENT OF THREADS Filed Apr ll 20, 1949 2 Sheets-Sheet l INVENTORS JOHN HARRISON GIVENS JOHN WALE LESLIE ROSE BY THEIR ATTORNEYS Dec. 5, 1950 Filed April 20, 1949 J. H. GIVENS ET AL APPARATUS FOR THE LIQUID TREATMENT OF THREADS 2 Sheets-Sheet 2 INVENTORS JOHN HARRISON GIVENS' JOHN WALE ATTORNEYS.

Patented Dec. 5, 1950 APPARATUS FOR THE LIQUID TREATMENT OF THREADS John Harrison Givens, Meriden, and John Wale and Leslie Rose, Coventry, England, assignors to Courtaulds Limited, London, England, a

British company Application April 20, 1949, Serial No. 88,584 In Great Britain May '7, 1948 12 Claims.

This invention relates to apparatus for the liquid treatment of threads.

In one of the so-called continuous spinning processes for the production of artificial threads, it is known to extrude a fibre-forming solution, normally viscose into a coagulating bath to form a multi-filament thread which is then carried on a pair of cylindrical or conical rollers, the axes of which are skewed with respect to one another, so that the thread is made to advance along the rollers in a helical path, and to subject the thread to desired liquid treatment for example washing, desulphurising and bleaching in separate liquid zones while the thread is advancing on the rollers. In this known process, it is common practice to arrange the axis of one roller or the axes of both of the rollers at a small angle with respect to the horizontal, so that the treating liquid flows along the roller, the flow being facilitated by the fact that the treating liquid wets the surface of the roller to form a continuous liquid film. It is highly desirable that the treating liquids supplied to the separate zones should be prevented from flowing into each other, otherwise the liquids may not be suitable for recirculation after recovery from the roller. Many proposals have already been made with a view to confining each liquid to its proper zone.

The object of the present invention is to provide improved apparatus in which the liquids supplied to each zone are confined to these zones without in any way obstructing the passage of the thread from one zone to the next.

In accordance with the present invention, a roller on the surface of which liquid treatment is effected has its surface divided into at least one liquid treating zone and a boundary zone the surface of which is not wetted by the liquid to be used so that the liquid supplied to the treating zone will not normally pass across the surface of the boundary zone.

The present invention also includes a roller on the surface of which liquid treatment is effected and which has its surface divided into at least two liquid treating zones separated by a boundary zone the surface of which is not wetted by the liquids to be used-so that liquid supplied to a treating zone will not normally pass across the surface of the boundary zone to a neighbouring zone. A roller having its surface divided into at least two liquid treating zones may have at least two boundary zones the surfaces of which are not wetted by the liquids to be used, one of these boundary zones separates two liquid treating zones and a second boundary zone s loca ed at one end of the surface of the roller 0r separates a liquid treating zone'from a drying zone. The provision of a boundary zone at one or both ends of the roller prevents the liquid from normally passing across the surface of the boundary zone or zones to the bearings supporting the roller.

In a, preferred form of the invention the boundary zone circumscribes the roller. The boundary zone may be formed by cutting an annular channel in the surface of the roller and filling the channel with a material which will not be wetted by the liquids used, so that the roller has an even thread supporting surface which offers very little or no resistance to the advancement of the threads but which nevertheless readily confines the treating liquids to the zone or zones defined by the band. or bands of non-wetting material.

In the scientific sense it is usual to define wetting in terms of the contact angle between the liquid and the solid surface. As the contact angle becomes greater, the work of adhesion becomes lower. Such definitions refer usually to stationary systems, and no such definitions are intended'in the case of the present invention, for which a simple test sufices to determine whether or not the work of adhesion of the particular liquid to the particular non-wetted material is sufficiently low for the liquid not to flow over it, and it is in this sense that the expression not wetted is used in this specification and claims. The material may be roughened to enhance this property and also to facilitate the removal of liquid droplets which may occasionall form on the surface of the boundary zones for example as a result of splashing.

Examples of suitable non-wetting materials which may be used to form the surface of the boundary zones in accordance with the present invention are solid polymers of ethylene corresponding to the formula (CH2) x usually known as polythene or solid polymers of tetrafiuoroethylene or solid interpolymers of tetrafluoroethylene with other polymerisable compounds, such as ethylene.

The dimensions of the boundary zone will depend to some extent on the particular nonwetting material forming the surface of the zone. For example, when using polythene as the non-wetting material the boundary zone may have a length of from one half to one inch in order to confine the treating liquids to the treating zones. The dimensions of the boundary zone will also depend on the rate of flow of the treating liquid to the roller. The roller must be provided with a surface which is resistant to the liquids used, for example, a roller for use in a machine for the treatment of artificial threads from viscose must be resistant to dilute aqueous solutions containing acids, metallic salts and bleaching agents and it must also be resistant to heat when a drying zone is included.

The roller in accordance with the present invention may be provided with one or more liquid treating zones and a drying zone and each of these zones may be separated by a boundary zone of non-wetting material. The drying zone may consist of an internally steam-heated zone but if desired the roller may be internally steam-heated along its length so as to obtain a more efiicient liquid treatment of the thread and to maintain the temperature of liquids applied to the roller.

The roller in accordance with the present invention is preferabl cylindrical, but may be oi any other suitable form, for example it may be tapering, frusto-conical or stepped to allow for stretching or relaxation of the thread passing over the roller.

The present invention also includes a machine for the production of artificial threads by extruding a thread-forming solution into a coagulating bath and passing the thread over a threadadvancing device incorporating a roller on the surface of which the thread is subjected to liquid treatment wherein the surface of the roller is divided into at least one liquid treating zone and a boundary zone the surface of which is not wetted by the liquid used so that the liquid sup plied to the treating zone will not normally across the surface of the boundary zone.

The thread advancing device incorporating the roller according to the present invention consist of the roller in combination with a stationary rod, the axis of which is canted with respect to the aXis of the roller or it may consist of pairs of rollers having their axes at an angle in the same or different planes in which at least one of the rollers has its surface divided into liquid treating zones and boundary zones.

When carrying out the production of artificial threads on a machine incorporating a roller in accordance with the present invention the thread formed may be subjected to two or more liquid treatments consecutively on a thread-advancing device and the liquids may be collected sepa rately and circulated for re-use or recovery without any substantial mixing of the liquids. The wet thread may be collected on a bobbin or in a centrifugal spinning box or the thread may be subjected to drying either on a separate device or a drying zone may be provided on the roller and may be defined by a boundary zone on the roller and the dried thread obtained collected in package form for example by a cap spinning device.

The present invention is illustrated by reference to the accompanying drawings in which:

Figure 1 shows a longitudinal section of a machine for the production of artificial threads equipped with a thread-advancing device incorporating a roller in accordance with the present invention, and

Figure 2 shows a longitudinal section of the thread-advancing device shown in Figure 1 on a larger scale.

Viscose from the main supply pipe I is passed through a pump 2, candle filter 3 and is extruded from the jet 4 into the coagulating bath 5 to form a thread 6. The thread 5 leaving the bath passes through the thread guide 7 and on to the,

stepped end 8 of the roller 9. The thread passes round the stepped end ll) of the roller l i and after passing round the stepped ends 8 and I!) for four turns it is led on to the main part of rollers 9 and II by means of a thread guide H2. The rollers 9 and II constitute a thread-advancing device on which the thread travels in a number of advancing helical turns. The rollers 9 and H are fixed on shafts l3 and M and are driven through gearing I5 and H6. The gearing i5 and I6 is protected from the liquids by the housing H. The roller II is provided With three bands I8, 19 and 20 of non-wetting material. The thread is treated with liquids supplied through pipes 2|, 22, 23 and 24 and used liquids are collected in drip pans 25, 26, 2? and 28 respectively. The bands l8, l9 and 26 of non-wetting material prevent the liquids from passing from one treatment zone to the next so that the liquids collected in the drip pans 25, 26, 27 and 28 can be recirculated or recovered. On reaching the end of the thread-advancing device 9 and H the thread leaves the roller 9 and passes down to a drying device 29. The drying device 29 consists of a rotating roller and a stationary rod 3!, the axis of which is canted with respect to the axis of the roller 30. The roller 38 is internally steam-heated so that the thread is dried as it travels along the roller. The dried thread leaves the drying device 29 and is collected as a package on the holder 32 by the cap-spinning device 33.

Examples of rollers according to the invention and their use in the liquid treatment of viscose rayon threads are described in the following examples. Percentages are by Weight.

Example 1 Viscose containing 8 per cent of cellulose, 6 per cent of sodium hydroxide, xanthated with 35 per cent carbon disu'phide calculated on the cellulose content and aged to a salt-point of 6.0 was extruded into a coagulat ng bath through a spinnerette containing 16 holes of /1000 inch diameter to produce a denier thread, the coagulating bath containing 9 per cent of sulphuric acid, 20 per cent of sodium sulphate and 1 per cent of zinc sulphate. The thread was withdrawn from the bath by a rotating godet having a peripheral speed of 60 metres per minute, and was then passed to a pair of canted thread-advancing ebonite rollers having a peripheral velocity of 66 metres per minute. The rollers were cylindrical, 6 inches in diameter and were arranged one above the other, 18 inches apart. The lower roller was arranged 3 from the horizontal, tilting downwards towards the entrance end of the rollers. The rollers were both 45 inches long and were separated into four approximately equal zones by 1 inch wide bands of polythene material inserted in annular channels in the rollers so that the surfaces of the bands were flush with the surface of the roller. In the first zone, the advancing thread, the separate helices of which were A; of an inch apart, was treated on the lower roller with 1 per cent aqueous sulphuric acid solution at to Centigrade to complete the regeneration of the thread. The second and third zones were water-washing zones, the second zone being supplied with water recovered from the third zone, which is supplied with fresh water. The fourth zone is a metal, steam-heated zone for drying the thread, The thread on leaving the fourth zone is collected on a cap-twisting device in known manner.

In this example, even when the liquid flow in the three liquid treating zones exceeds 300 cubic centimetres per minute, no carry over of treating liquid occurs, and the liquid from the rollers within the separate zones may be collected without pollution for re-use or disposal.

Example 2 The procedure described in Example 1 was repeated but in this case the zones of liquid treatment were bounded and separated by V inch bands of polytetrafluoroethylene, the bands being flush with the surface of the rollers.

Example 3 The procedure described in Example 1 was repeated but in this case the polythene material separating the liquid zone is roughened by abrading fine scratches upon it, in order to lower the work of adhesion and to facilitate the removal of liquid droplets occasionally formed on the bands.

What we claim is:

1. A roller on the surface of which liquid treatment is to be effected, having at least one liquid treating zone with a surface of material which is wetted by the liquid to be used and a boundary zone with a surface of material which is not wetted by the liquid to be used so that the liquid supplied to the treating zone will not normally pass across the surface of the boundary zone.

2. A roller on the surface of which liquid treatment is to be effected, having at least two liquid treating zones separated by a boundary zone, the surface of each liquid treating zone being of material which is wetted by the liquid to be used and the surface of the boundary zone being of material which is not wetted by the liquid to be used so that the liquid supplied to a treating zone will not normally pass across the surface of the boundary zone to a neighboring zone, the

surface of the boundary zone being a continuous,

even, thread-supporting surface, whereby the thread is not subjected to changes in length while passing across the boundary zone from one liquid treating zone to an adjacent liquid treating zone.

3. A roller on the surface of which liquid treatment is to be effected, having at least two liquid treating zones separated by a boundary zone, the surface of each liquid treating zone being of material which is wetted by the liquid to be used and the surface of the boundary zone being of material which is not wetted by the liquid to be used so that the liquid supplied to a treating zone will not normally pass across the surface of the boundary zone to a neighboring zone.

A roller on the surface of which liquid treatment is to be effected, having at least two liquid treating zones, with surfaces of material which is wetted by the liquids to be used, and at least two boundary zones with the surfaces of material which is not wetted by the liquids to be used, one boundary zone separating two liquid treating zones and another boundary zone separating a liquid treating zone from one end of the roller.

5. A roller on the surface of which liquid treatment is to be effected, having at least one liquid treating zone with a surface of material which is wetted by the liquid to be used, and a boundary zone with a surface of material which is not wetted by the liquid to be used and is se- 6 lected from the group consisting of solid polymers of ethylene, solid polymers of tetrafluoroethylene and solid interpolymers of tetrafluoroethylene and ethylene so that the liquid supplied to the treating zone will not normally pass across the surface of the boundary zone.

6. A machine forthe production of artificial threads by extruding a thread-forming solution into a coagulating bath and'passing the thread over a thread-advancing device incorporating a roller on the surface of which the thread is subjected to liquid treatment, wherein the surface of the roller is divided into at least one liquid treating zone with a surface of material which is wetted by the liquid used and a boundary zone with a surface of material which is not wetted by the liquid used so that the liquid supplied to the treating zone will not normally pass across the surface of the boundary zone.

7. A machine for the production of artificial threads by extruding a thread-forming solution into a coagulating bath and passing the thread over a thread-advancing device incorporating a roller on the surface of which thread is subjected to liquid treatment, wherein the surface of the roller is divided into at least two liquid treating zones separated by a boundary zone, the surface of each liquid treating zone being of material which is wetted by the liquids used and the surface of the boundary zone being of material which is not wetted by the liquids used so that liquid supplied to a treating zone will not normally pass across the surface of the boundary zone to a neighboring zone.

8. A machine for the production of artificial threads by extruding a thread-forming solution into a coagulating bath and passing the thread over a thread-advancing device incorporating a roller on the surface of which thread is subjected to liquid treatment, wherein the surface of the roller is divided into at least two liquid treating zones with the surfaces of material which is wetted by the liqu ds used and at least two boundary zones with the surfaces of material which is not wetted by the liquids used, a boundary zone separating the two liquid treating zones and another boundary zone separating a liquid treating zone from one end of the roller.

9. A roller as claimed in claim 5 wherein the surface of the boundary zone consists of a solid polymer of ethylene.

10. A roller as claimed in claim 5 wherein the surface of the boundary zone consists of a solid polymer of tetrafluoroethylene.

11. A roller on the surface of which liquid treatment is to be effected, having at least two liquid treating zones with surfaces of material which is wetted by the liquids to be used, a drying zone and at least two boundary zones with surfaces of material which is not wetted by the liquids to be used, one boundary zone separating two liquid treating zones, and another boundary zone separating a liquid treating zone from the drying zone.

12. A machine for the production of artificial threads by extruding a thread-forming solution into a coagulating bath and passing the thread over a thread-advancing device incorporating a roller on the surface of which thread is subjected to liqu d treatment, wherein the surface of the roller is divided into at least two liquid treating zones with the surfaces of material which is wetted by the liquids used, a drying zone and at least two boundary zones with the surfaces of material which is not wetted by the liquids 7 8 used, one boundary zone separating two liquid REFERENCES CITED treating zones and another boundary zone sepa- The following references are of record in the rating a. liquid treating zone from the drying file of this patent: zone.

JOHN HARRISON GIVENS 5 UNITED STATES PATENTS JOHN WALE- Number Name Date LESLIE ROSE. 2,416,533 Naumann Feb. 25, 1947 

1. A ROLLER ON THE SURFACE OF WHICH LIQUID TREATMENT IS TO BE EFFECTED, HAVING AT LEAST ONE LIQUID TREATING ZONE WITH A SURFACE OF MATERIAL WHICH IS WETTED BY THE LIQUID TO BE USED AND A BOUNDARY ZONE WITH A SURFACE OF MATERIAL WHICH IS NOT WETTED BY THE LIQUID TO BE USED SO THAT THE LIQUID SUPPLIED TO THE TREATING ZONE WILL NOT NORMALLY PASS ACROSS THE SURFACE OF THE BOUNDARY ZONE. 